Редагувати

Поділитися через


ExpressionsCollectionEditor.EditValue Method

Definition

Edits the value of the specified object with the specified service provider and context.

public:
 override System::Object ^ EditValue(System::ComponentModel::ITypeDescriptorContext ^ context, IServiceProvider ^ provider, System::Object ^ value);
public override object EditValue (System.ComponentModel.ITypeDescriptorContext context, IServiceProvider provider, object value);
override this.EditValue : System.ComponentModel.ITypeDescriptorContext * IServiceProvider * obj -> obj
Public Overrides Function EditValue (context As ITypeDescriptorContext, provider As IServiceProvider, value As Object) As Object

Parameters

context
ITypeDescriptorContext

An ITypeDescriptorContext object that can be used to gain additional context information such as the associated control.

provider
IServiceProvider

A service provider object through which editing services can be obtained.

value
Object

An instance of the object being edited.

Returns

An ExpressionBindingCollection object containing the selected expressions; otherwise, if no expressions are selected, the value object.

Remarks

The EditValue method launches the user interface for editing the value object. The designer host calls the EditValue method when you attempt to edit the value of a property that this editor is associated with. The input service provider is used to obtain any editing services that are required within the EditValue.

A designer host, such as Visual Studio 2005, uses the ExpressionBuilder and ExpressionEditor class implementations with the ExpressionsCollectionEditor and ExpressionsCollectionConverter classes to set the expression bindings for control properties at design time, and the ControlPersister class to persist the expressions for run time. Expression strings reference a localizable resource, an application setting, a connection string, or a custom expression type. The expression string is bound to the control property at design time, and then used at run time to determine the value for the property.

If users cancel the user interface without modifying the expression binding collection, the EditValue method returns the input value parameter.

Applies to

See also